TOKYO — Japan’s bureaucratic rank and file march in dark jackets and ties to government offices every day, sweating their way through the country’s sticky, sweltering summers.

Starting Wednesday, they’ll be sweating a little less.

In a nationwide campaign to save energy by cutting down on air-conditioning, the government has asked public workers to leave their ties and jackets home for the summer.

Many people would have no problem with that but in Japan, where conformity and tradition are prized, workers find it tough to comply. To persuade them to set their inhibitions aside, the effort, dubbed “Cool Biz,” has enlisted help from the highest authorities.

Prime Minister Junichiro Koizumi recently showed up in a newspaper advertisement wearing a half-sleeve shirt with no tie, urging his Cabinet to follow suit.

“If the ministers are wearing a tie, their subordinates would feel uneasy about not wearing it,” he said a few weeks ago. “So the ministers should not wear a tie.”

Air conditioners set to 82The Environment Ministry campaign has nothing to do with loosening up Japan’s stodgy government ministries — and everything to do with meeting targets under the Kyoto global warming protocol. Tokyo needs to cut so-called greenhouse gas emissions to 6 percent below 1990 levels by 2012.

To help make the goal, air conditioners in government buildings will be set at a toasty 82, the maximum allowed by law. Offices usually keep the temperature at around 77.

Some private companies already allow employees to dress casually for summer. But the government endorsement is expected to make casual attire more acceptable.

The Energy Conservation Center estimates if all offices in Japan increase summer temperatures to 82, it could save 81 million gallons of oil in one summer.

Dressing down manualTo rally support, and reassure bureaucrats unfamiliar with being laid-back, the Environment Ministry has released a manual on dressing down — with hints such as matching the colors of your belt and shoes.

“We try to explain why just untying your necktie won’t do. We show how to achieve an acceptable business look without wearing a tie,” said Kentaro Doi, the ministry official in charge of the campaign.

The ministry is even planning a “Cool Biz Collection” fashion show June 5 at the 2005 World Expo in Aichi, with top executives — including Toyota chairman Hiroshi Okuda — strutting down the runway.

The new policy is expected to boost the economy, as the country’s 250,000 national bureaucrats retool their monochromatic wardrobes. Economy Minister Heizo Takenaka said the effort could raise consumer spending by at least $92 million.

That rises to $5.6 billion if local government and private industry workers are included.

Shirt sales upThe effort seems to be having some effect. At a major Tokyo department store, Nihonbashi Mitsukoshi, men’s shirt sales were up 17 percent in May from the same month last year, according to men’s section salesman Eiji Utsunomiya.

The store features shirts with hidden snaps or extra buttons so the collar stays upright without a tie.

“It was unacceptable 10 years ago. But I think people are ready for new fashion, and society is changing so we are less resistant to change,” Utsunomiya said.

But judging from the past, success is not guaranteed.

In 1979, after the second “oil shock,” Prime Minister Masayoshi Ohira introduced a “save energy look,” wearing a half-sleeve suit and tie. It was a failure. A 1994 attempt by Prime Minister Tsutomu Hata also flopped.

A salesman, Katsuyuki Ishii, predicted yet another failure.

“My company has no such plans. I know it is even unpleasant to look at us,” he said, gesturing at his jacket and tie. “But it’s like a uniform.”